Surface skimmer



March 13, 1934. s. J. BLAKE SURFACE SKIMMER Filed Aug. 8, 1953 [fw @M072- SHE/QM/q/v J 5L 4K5,

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Patented Mar. 13, 1934 SURFACE SKIMMER Sherman J. Blake, Conneaut, Ohio Application August 8,' 1933, Serial No. 684,272

3 Claims.

This invention relates to surface skimmers for liquids and more particularly to devices for removing scum which accumulates on the surface of the water in steam boilers.

` 5 In steam boiler practice, for whatever purpose,

it is a well known fact that considerable trouble and expense results from the accumulation of foreign matter or impurities that are carried to the surface of the water as its temperature rises. If not removed, these impurities harden and form scale, which results in lack of efficiency and the ultimate destruction of the boiler.

One object of the present invention is the provision of a novel device for completely and automatically removing any foreign matter or impurities from the surface of the Water in boilers and similar vessels and which, once installed, will require no attention or adjustments.

Another object is to provide a novel device of the class described which may be easily and cheaply manufactured, easily installed and will be very durable in service.

These and further objects will be apparent after referring to the drawing, in which:

Figure 1 is a sectional elevation of the device of the invention as applied to a standard type of boiler.

Figure 2 is an elevation shown partly in section and taken on the line II-II of Figure 1.

Figure 3 is a sectional view on the line III-III of Figure 2.

Referring more particularly to the drawing, the letter A designates a fragmentary portion of a conventional type of boiler having the usual 1 35 stays B.

According to the teaching of the invention, a support C is secured to the stays B in any suitable manner and carries a thimble 2 to which there is connected a vertically disposed tube 3.

A sleeve 4 is provided with a portion 5 of reduced diameter and secured to the lower end of the tube 3. A hollow piston 6 is provided with a shortened portion 7 of reduced diameter that is adapted to slide on the vertically disposed tube 3 and make contact at its lower end with the exterior of the sleeve 4.

The hollow piston 6 is provided with a continuous ange 8 for supporting a tray 9, and has a plurality of apertures as at 8a adjacent the bottom of the latter.

A spring 10 is disposed within the hollow piston 6 for biasing it away from the sleeve 4 which has a plurality of apertures 4 for enabling communcation between the interior of the piston and the bore of the vertically disposed tube 3.V

A circular plate 12 is secured to the lower end of the sleeve 4 and provided with a removable plug 14.

A pair of rods 15 are made to extend through the plate 12, circular flange 8 and thimble 2 and are suitably secured to the support C, as by means of the nuts 16.

A discharge pipe 17 is connected to the thimble 2 and made to extend through the boiler A on the exterior of which it is provided with a Valve 18.

In operation, the opening of the valve 18 produces a iiow of steam from the boiler through the apertures 8a in the hollow piston 6 and also through the apertures 4a in the sleeve 4, and thence through the vertically disposed tube 3 and out through the discharge pipe 17. This flow of steam causes a drop in pressure in the hollow piston 6, resulting in the steam pressure in the boiler forcing the piston and tray downwardly against the inuence of the spring 10.

The amount of drop in the pressure and also the vertical position of the tray 9 is dependent on the relative orifice areas of the apertures 8a and 4a.

(Dwing to the physical characteristics of steam and water flowing through the orifices, the steam in flowing produces a greater drop in pressure than does water when flowing through the same orifices. That is to say, with steam flowing the tray 9 is lowered farther than when water is flowing.

The steam will, of course, lower the tray and when the edge is under water the latter will naturally commence to flow. This action causes the pressure to raise in the hollow piston 6 with the Vresult that it will move upwardly with the tray 9 untii the latter is above the surface of the water. The valve 18 is then closed until the function of the device is again required.

In use, it will be found that the hollow piston 6 reaches a stable height with water and some steam iiowing, which will maintain the edge of the tray 9 slightly under water. The surface water, foreign matter and impurities may be removed from the boiler at any water level within the operating range of the device.

While I have shown and described one specinc embodiment of my invention, it will be understoodV that I do not wish to be limited exactly thereto, since various modifications may be made without departing from the scope of my invention, as defined in the following claims.

I claim:

1. A surface skimmer for liquidscomprising a support, a vertically disposed tube secured to said support, a pipe in communication with said tube, a sleeve secured to the lower end of said tube, a hollow piston mounted for sliding movement on said tube and said sleeve, a tray supported by said hollow piston, and resilient means for maintaining said tray adjacent the surface of said liquid, said hollow piston and said sleeve having apertures to permit the ilow of liquid from said tray through said discharge pipe.

2. A surface skimmer for steam boilers comprising a support connected to the stays in said boiler and carrying a vertically disposed tube, a discharge pipe in communication with said tube and extending through said boiler, a valve in said discharge pipe on the exterior of said boiler, a sleeve secured to the lower end of said tube, a hollow piston mounted for sliding movement on said tube and said sleeve, a tray supported by said hollow piston, a spring for biasing said hollow piston away from said sleeve in such manner as to maintain said tray adjacent the surface of the water in said boiler, said hollow piston and said sleeve having apertures to permit theilow of liquid from said tray through said discharge pipe by the opening of said valve, and means enabling the removal of sediment from said sleeve.

3. A surface skimmer comprising a support, a thimble secured to said support, a vertically disposed tube secured to said thimble, a discharge pipe connected to said thimble and extending through the vessel containing the liquid, a valve in said discharge pipe on the exterior of said vessel, a sleeve secured to the lower end of said tube, a hollow piston mounted for sliding movement on said tube and said sleeve, a tray supported by said hollow piston, a spring for biasing said hollow piston away from said sleeve in such manner as to maintain the upper edge of said tray adjacent the surface of the liquid, said hollow piston and said sleeve having apertures to permit the flow of liquid from said tray through said discharge pipe, a plate secured to the lower end of said sleeve, a removable plug in said plate and at least one rod adapted to extend through said plate, said tray and said thimble, and adapted to rigidly connect said elements to said support.

SHERMAN J. BLAKE. 

